of wellington



Mar. 6, 1923.

H. s. CEDERHOLM GAS IGNITER Filed Mar.

Patented Mar. 6, 1923.

UNITED STATES PATENT OFFICE.

HALFORD SIGFRID CEDERHOLM, QF WELLINGTON, NEW ZEALAND, ASSIGNQR OF ONE-'HALF TO ELIAS JOS. HYAMS. OF WELLINGTON, NEW ZEALAND.

GAS IGNITER.

Application filed March 3, 1921. Serial No. 449,354.

To all whom it may concern:

Be it known that I, HALroRn SIGFRID Cronin-10ml, a citizen of the Dominion of New Zealand. residing at 68 Manners Street, Wellington, in the Provincial District of \Vellington, a subject of the King of Great Britain and Ireland. have invented certain new and useful Improvements in Gas lgniters, of which the following is a specification.

This invention relates to that class of gas igniter which has a fine platinum wire or wires supported by wires one of which is insulated and passes into a casing containing a dry electric battery. the other of said supporting wires being connected electrically tothe removable cap of the casing, the bottom of which is perforated, in order to permit of the battery being pushed in the easing to complete an electric circuit.

The present invention provides improve ments which simplify the construction of igniters 01 this class thereby reducing the cost of the latters production and enabling fresh batteries to be placed in the casing by unskilled persons.

An igniter according to the invention has the casing permanently closed at the upper end and open at the lower end. The inside of the latter has formed therein a circular groove to take an open spring ring which retains the battery in the casing. One of the supporting wires for the platinum wire or wires passes centrally through insulation held in a ferrule screwing into the closed end of the casing and into which said wire projects. The other of said supporting wires is electrically connected to the terrule.

The terminal on the battery is kept normally separated from the lower end of the supporting wire entering the casing by means of a spiral spring placed loosely in the casing between the battery and the easing top. 7

The shell of the battery. and the casing are formed of metal to serve as conductors of electricity and make contact with each other.

The invention will be more particularly described with reference to the accompany ing drawing in which Figure 1 is a sectional elevation of the igniter when not in use.

Figure 2 is a sectional elevation of the igniter with the battery pushed into the casing to complete the electric circuit, and

Figure 3 illustrates the platinum wires and their supports.

The casing l and the shell of the battery 2 are formed of metal suitable for conducting electricity, said casing being closed at one end by the permanently fixed top 3 and being open at the lower end.

The platinum wires t are arranged in the bow shape to allow for contraction and expansion. and thus prevent breakage of the wires under the high range of temperature to which they are subjected. At their lower ends the wires 4 are electrically connected to a. supporting wire 5 which passes centrally through and is insulated from the metal t'errule 6 which screws into the fixed top 3. The wire 5 projects below the ferrule 6 into the casing 1.

The upper ends of the wires 4 are electrically connected to the supporting wire 7 which in turn is electrically connected to the ferrule 6.

The battery 2 has a terminal 8 on its upper end said terminal being kept nor mally forced away from and out of contact with the lower end of thewire 5 by the spiral spring 9 placed between the battery 2 and top 3 without being secured to either or to the casing.

The top of the battery 2 on which the spring rests is sealed by non conducting material 2 The battery 2 is prevented from leaving the casing l by the open wire ring 10 sprung into the circular groove 11 around the inside of the lower end of the casing.

A disc 12-of suitable material is preferably placed between the ring 10 and the battery 2 mainly for the purpose of improving the appearance of the lower end of the device. Instructions or other printed matter can be placed on the exposed side of the disc.

The wires l. 5 and T are enclosed in a perforated cover 13 attached to the ferrule (5.

Vhen the battery 2 is pushed into the casing 1 as far as it will go the terminal 8 makes contact with the lower end of the wire 5 and closes the electric circuit, the current 105 passing through the battery terminal 8, wires 5. 4 and '7. ferrule 6, top 3, casing 1 and shell of the battery. back into the latter.

As the top of the battery on which the spring 9 rests is sealed with non conducting material and the spring 9 is of such a diameter that it cannot touch the terminal 8, a short circuit is prevented from occurring between the top 3 and the terminal 8 through the spring 9.

By leaving the spring, loose or unattached to any part which is not done in igniters of this class as at present used, a fresh battery can be placed in position and the ignite!- recharged by persons unskilled in the use of tools.

The wires 4: are heated only when the electric circuit is closed and it then exposed to escaping gas cause instantaneous ignition of the latter. 1

What I do claim and desire to obtain by Letters Patent of the UnitedStates is 1. A gas igniter comprisin g a casing having a permanently closed upper end and an open lower end provided with a groove. incandescible wires electrically connected to supporting wires one of which projects and is insulated from said casing. while the other of said supporting wires is electrically connected with said casing; a battery making electrical contact with and slidable in said casing. having a terminal kept normalh separated from the lower end of said insua; lated supporting wire by a spring insulate from the terminal of said battery; and ring sprung into the groove in the casu g below the batter for retaining the latter in the casingsubstantially as described and illustrated.

2. In a gas igniter ol' the ltind described, a casing having a permanentl; closed upper end, supporting; means carried by said casin; adapted to support fine platinumwires, said casing having an open lower end provided with a groove and an open ring adapted to be sprung into said groove for maintaininc anelectric batter in position in the casing.

3. In a gas igniter, a casing having an open end, an incandescible member carried by the opposite end of the casing, a battery. 

